Sanders-Phillips, Kathy Significant disparities exist in rates of HIV/AIDS in the United States and African Americans have the highest infection rates in the country. Therefore, this proposal to examine behavioral and biological factors that may be related to HIV/AIDS in African American young adults is resubmitted in response to RFA-MD- 12-001 for NIMHD Health Disparities Research. A primary goal of the research is to develop a predictive model to identify subgroups of African American (AA) young adults who, based on their exposure to urban violence, may be at greater risk for exposure to HIV and should be targeted for prevention. In keeping with a focus of RFA-MD-12-001 on the social determinants of diseases such as HIV/AIDS that disproportionately affect ethnic-racial minorities, this within-group, longitudinal study of male and female African American young adults living in low-income, urban communities conceptualizes HIV/AIDS as a health problem that may be influenced by exposure to environmental stressors such as interpersonal and community violence. The high rates of violence in many urban communities may increase vulnerability to HIV/AIDS in African American young adults by impacting behavioral and biological pathways. First, exposure to interpersonal and community violence may be related to greater drug use and sexual risk-taking (e.g., multiple partners; failure to use condoms) that increase the probability f exposure to HIV. Chronic exposure to violence in multiple contexts (e.g., home and community) may exacerbate this effect. While drug use and sexual risk-taking are the primary risk factors for exposure to HIV in the U.S., there is increasing evidence that exposure to violence may also be associated with immune system dysregulation that results in a decrease in the ability of the immune system to effectively respond to infections and/or other foreign materials. Evidence of immune system dysregulation includes heightened levels of antibodies to the Epstein Barr Virus (EBV) and C reactive protein (CRP). Previous findings indicate that these biomarkers (EBV, CRP) are related to HIV acquisition and seroconversion. Thus, immune system dysregulation may be related to greater susceptibility to viral infections like HIV and an increased likelihood o contracting AIDS if exposed to the HIV virus. Existing data also strongly suggest that symptoms of depression subsequent to violence exposure may be a moderating variable that is related to increases in drug use, sexual risk-taking and dysregulation of the immune system. While animal studies support these associations, longitudinal studies of violence exposure and immune function in human groups, especially African Americans living in urban areas, have not been conducted. Therefore, the degree to which immune function may be suppressed in this population has not been examined empirically and the role of immune system dysregulation as a potential co-factor that may contribute to higher rates of AIDS in African Americans has not been established. Given recent data indicating possible sex differences in immunological responses to viruses, it is also important to examine gender as a variable that may influence relationships between violence exposure and immune function. This study will assess the impact of exposure to interpersonal and community violence on depression (symptoms of depression and clinical depression), ATOD use (alcohol, tobacco and other drug), HIV risk behaviors (condom use, number of sexual partners), and immune system function (antibodies to EBV, CRP levels) in African American young adults aged 18-25 (n = 600). Behavioral data, collected via computerized surveys, and biological data will be collected at baseline and at one and two-year follow-ups. Potential confounding variables (e.g., dietary patterns, other life stressors, coping strategies, health status) will also be assessed. The proposed study is unique and innovative in its focus on features of the urban context that, over time, may influence HIV/AIDS risk in African American young adults. The findings may have implications for the use and/or development of medications to decrease the risk of HIV/AIDS in African American young adults exposed to high levels of violence. For example, antidepressants may normalize depressive symptoms by exerting effects on immune system function and statins may reduce inflammation by decreasing levels of CRP. The study findings may also have implications for existing HIV/AIDS prevention programs. For example, to identify potentially modifiable protective factors that could be addressed in current HIV/AIDS prevention programs for African American young adults, this study will examine and identify coping strategies that are associated with HIV prevention behaviors (i.e., condom use) in the sample. Existing HIV/AIDS prevention and intervention programs may need to target African American young adults who have been exposed to high levels of urban violence and promote effective strategies for coping with violence in their programs.